Capsule opacification with 2 different IOLs: 3-year results
This follow-up study found anterior capsule opacification development and anterior capsule retraction to be more frequent 3 years after cataract surgery when an IOL with interrupted sharp optic edge at the optic–haptic junction is implanted, compared with an IOL with a continuous edge.
Take-home message: This follow-up study found anterior capsule opacification development and anterior capsule retraction to be more frequent 3 years after cataract surgery when an IOL with interrupted sharp optic edge at the optic–haptic junction is implanted, compared with an IOL with a continuous edge.
By Faye Emery; Reviewed by Dr Guenal Kahraman
Dr. Guenal KahramanThe material and design of intraocular lens’ (IOL), especially at the optic edge, are both relevant factors when it comes to anterior (ACO) and posterior capsule opacification (PCO) development.1–4 Sharp optic edges have previously been shown to prevent migration of epithelial cells between the capsular bag and the IOL.1–3 In this study, the authors evaluated and compared the degree of PCO, ACO and anterior capsule retraction, 3-years after implantation of 2 different single-piece hydrophobic acrylic IOLs. One of the implanted lenses featured a 360-degree continuous sharp optic edge (Tecnis ZB00, Abbott Medical Optics, Inc., Illinois, USA) whereas the other had an interrupted square edge (Acrysof SA60AT, Alcon Surgical, Inc., Surrey, UK).
Patient follow-up
Between October 2009 and September 2013, 80 patients who had previously undergone uneventful phacoemulsification with bilateral senile cataract that induced a significant visual deterioration were enrolled in the study at the Hospital of St. John of God (Vienna, Austria).5 Each patient randomly received 1 IOL model in 1 eye and the other model in the fellow eye by the same surgeon.
During follow-up visits, a complete ophthalmologic examination including slitlamp biomicroscopy, applanation tonometry, and fundus examination were performed. The ACO grading was carried out subjectively with a slitlamp by 1 experienced examiner. The Evaluation of Posterior Capsule Opacification (EPCO) software developed by Tetz et al.6 was used to quantify PCO.
During the final follow-up visit, 3-years post-implantation, the investigators were able to analyse images of 50 patients (100 eyes) out of the original 80 (Figures 1-3). Patient age ranged from 61 to 80 years with a mean value of 70.2 years ± 9.3 (SD).
(Figure 1) Scattergram showing the relationship between the PCO level 3 years postoperatively in eyes implanted with the Acrysof IOL (group A), and eyes implanted with the Tennis IOl (group B). Each circle corresponds to one patient.
Differing outcomes between PCO and ACO
No significant differences in PCO score were found between Acrysof IOL and Tecnis IOL. (3 year follow-up visit: Acrysof 0.23 ± 0.36 versus Tecnis 0.22 ± 0.32, P = 0.66). Anterior capsule opacification was present in Acrysof 18.0% and Tecnis 2.7% (P = 0.03) and in 92.0% and 24.0% of eyes (P < 0.01) at 1 and 3 years after surgery, respectively.
The authors noted that low mean PCO scores were obtained with both types of IOL, with no significant differences between them throughout the follow-up period. It was suggested that IOL material was a crucial factor for the observed low levels of PCO. However, when it came to analysing the ACO results, outcomes were very different to those found for PCO. Significantly higher percentages of ACO and overall higher scores were observed in eyes implanted with the interrupted square optic edge IOL compared to those implanted with the continuous square optic edge IOL. As each type of IOL was implanted in fellow eyes of the same patient (thus the study was an intraindividual comparison), the authors suggested differences in IOL surface properties and design as an explanation for this finding.
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